Cells in a Range on an Excel Sheet LeetCode solution in JavaScript

1
const toCharCode = (char) => char.charCodeAt();
2

3
var cellsInRange = function (s) {
4
  const result = [];
5
  for (let i = toCharCode(s[0]); i <= toCharCode(s[3]); i++) {
6
    for (let j = s[1]; j <= s[4]; j++) {
7
      result.push(String.fromCharCode(i) + j);
8
    }
9
  }
10
  return result;
11
};